New hope in the fight against cancer: Smart drugs

Approximately 10 million people worldwide die from cancer each year. This demonstrates that cancer is not only a medical crisis but also a societal one. Chemotherapy, which has been the cornerstone of treatment for many years, aims to destroy the rapidly dividing cells that cause cancer, but it also causes significant damage to healthy tissue. This damage also leads to its significant side effects. Therefore, scientists have long sought to develop methods that specifically target cancer cells. Hundreds, even thousands, of studies have been conducted on this topic. As a result, new treatment methods known as "smart drugs" have begun to be developed.

These smart drugs can recognize certain molecules specific to cancer cells and distinguish them from healthy cells. Some smart drugs directly inhibit the activities of cancer cells. Because these inhibited activities are not present in healthy cells, they do not cause off-target damage. This means their side effects are extremely minimal. Another type of smart drug is inhibitors, which work in conjunction with our immune system to kill cancer cells. Our immune system immediately responds to foreign elements entering the body but does not recognize cancer cells as foreign. These drugs, in turn, identify cancer cells as foreign to our immune system.

A TURNING POINT: IMATİNİB

Every healthy cell goes through several checkpoints before dividing. If abnormalities are detected at these points, the cell attempts to correct the situation or is prevented from dividing, or may even sacrifice itself to prevent harm to other cells. If everything is in order, the cell divides and continues its natural life. However, cancer cells cannot be stopped at these checkpoints. Therefore, the most well-known characteristic of cancer cells is their rapid and uncontrolled division. This allows them to rapidly increase in number and easily take over the tissue in which they reside.

Imatinib targets tyrosine kinase enzymes, which cause cancer cells to divide rapidly and uncontrollably. Used in many cancer treatments, this drug works by inhibiting the activity of these enzymes, preventing cancer cells from dividing. Imatinib, which entered clinical use in the early 2000s, is considered a breakthrough in cancer treatment because it is one of the most effective targeted therapy drugs developed. Similarly, the drug trastuzumab targets breast cancer cells with excess HER2 protein, interrupting their growth signals. This selective effect both increases success rates and reduces the side effects seen with conventional chemotherapy.

Releasing the Immune System

One of the methods that have revolutionized cancer treatment in recent years is immune checkpoint inhibitors. These drugs follow a different strategy than traditional smart drugs. Normally, the immune system has certain "braking" mechanisms to protect the body from its own cells. Cancer cells exploit these brakes, preventing immune cells from recognizing them. By eliminating these brakes, immune checkpoint inhibitors enable the immune system to detect the cancer again.

PD-1 and CTLA-4, two of the most frequently targeted proteins, are among the key molecules that limit the activity of immune cells. Thanks to drugs developed against these proteins, T cells are reactivated and can attack tumor cells. Clinical studies have shown that the impact of cancer is reduced, particularly in deadly cancers such as skin cancer and lung cancer. Thus, this approach, which fights cancer by strengthening the immune system, has become one of the most promising treatment methods in modern oncology.

PERSONALIZED MEDICINE

Cancer cells owe their ability to evade these checkpoints to the mutations they possess. These mutations disrupt the nature of healthy cells and can transform them into cancer cells. Through their research, scientists have discovered that these mutations can vary across cells, cancer types, and even patients. In other words, the cancer-causing mutations in two breast cancer patients may target different proteins. This suggests that different treatment methods should be employed, targeting different proteins or enzymes.

With today's technology, scientists can now take samples of cancerous tissue and analyze them. This allows them to determine the most appropriate drug and treatment method for each patient. This significantly increases the success rate of treatment. These drugs, tailored to the tumor's genetic characteristics, signal the end of the era of "one-size-fits-all" and the rise of personalized medicine.

While the possibilities offered by smart drugs are promising, the development of resistance in tumor cells remains one of the biggest obstacles. Despite this, scientists are working on new molecules that can simultaneously affect multiple targets and overcome the resistance problem. Today, smart drugs are not just a hope in cancer treatment; they are a growing reality. Personalized treatments supported by genetic analysis and biomarkers are ushering in a completely new era in oncology.